The present invention relates to travel of personnel along a flexible support member or purposes of reducing the risk of injury and/or reaching relatively inaccessible places.
Various circumstances give rise to the need for travel along a rope or other flexible support member. For example, people are sometimes required to rapidly evacuate an elevated structure. Other situations arise where people find it necessary to move relative to a steep support surface and/or within an open space. In order to facilitate such activity and address safety issues associated therewith, a variety of devices, including descenders, rope grabs, and hoists have been invented and/or manufactured. However, room for improvement remains.
The present invention provides methods and apparatus for safely traveling along a flexible support member. A preferred embodiment of the present invention may be described as a descender which allows a person to move down a flexible support member at a controllable speed. However, those skilled in the art will recognize that the principles of the present invention may be applied to other types of devices, including fall arresting rope grabs, for example.
A preferred embodiment of the present invention includes a plurality of bearing members movable mounted between opposing plates. A flexible support member is routed about the bearing members in a manner which forms a knot. An operator is linked to the bearing members and operable to change an effective perimeter defined by outwardly facing portions of the bearing members. The size of the perimeter determines the tightness of the knot, which in turn determines the extent to which the apparatus resists movement along the fexible support member. Additional features and/or advantages of the present invention may become more apparent from the detailed description which follows.